The terms "overbased", "superbased", and "hyperbased", are terms of art which are generic to well known classes of metal-containing materials which for the last several decades have been employed as detergents and/or dispersants in lubricating oil compositions. These overbased materials which have also been referred to as "complexes", "metal complexes", "high-metal containing salts", and the like, are characterized by a metal content in excess of that which would be present according to the stoichiometry of the metal and the particular organic compound reacted with the metal, e.g., a carboxylic or sulfonic acid. In recent times, the increasing costs and scarcity of petroleum has made it increasingly desirable to replace oil-based compositions with aqueous systems wherever possible. Other benefits can also flow from such replacements such as decreased fire hazard and environmental pollution problems. In many cases, however, it is not feasible to make such replacements because the aqueous systems cannot be modified in their properties so as to perform to the same high degree as their oil-based counterparts do. For example, it has been often difficult, and even impossible to replace certain oil-based hydraulic fluids with water-based fluids even though the desirability of doing so is evident.
Newtonian overbased materials and non-Newtonian colloidal disperse systems comprising solid metal-containing colloidal particles predispersed in a disperse medium of at least one inert organic liquid and a third component selected from the class consisting of organic compounds which are substantially insoluble in said disperse medium are known. See, for example, U.S. Pat. Nos. 3,492,231; and 4,230,586.
Carboxylic acid derivatives made from high molecular weight carboxylic acid acylating agents and amino compounds and their use in oil-based lubricants are well known. See, for example, U.S. Pat. Nos. 3,216,936; 3,219,666; 3,502,677; and 3,708,522.
Certain alkyl succinic acid/alkanol amine condensates have also been described; see, for example, U.S. Pat. No. 3,269,946. Water-in-oil emulsions containing alkyl and alkenyl succinic acid derivatives are also known; see, for example, U.S. Pat. Nos. 3,255,108; 3,252,908 and 4,185,485.
Surfactants are also well known. See, for example, the text entitled "Non-ionic Surfactants" edited by M. J. Schick, published by Marcel Dekker, Inc., New York, 1967 and McCutcheon's "Detergents and Emulsifiers", 1978, North American Edition, published by McCutcheon's Division, MC Publishing Corporation, Glen Rock, N.J., U.S.A.
Oil-soluble, water-insoluble functional additives are also well known. See, for example, the treatises by C. B. Smalheer and R. Kennedy Smith, published by Lezius-Hiles Co., Cleveland, Ohio, 1967, and by M. W. Ranney, published by Noyes Data Corp., Parkridge, N.J., 1973 entitled "Lubricant Additives". In this connection, and throughout the specification and appended claims, a water-insoluble functional additive is one which is not soluble in water above a level of about 1 gram per 100 milliliters of water at 25.degree. but is soluble in mineral oil to the extent of at least one gram per liter at 25.degree..
It would be advantageous to provide aqueous compositions containing overbased materials and optionally other functional additives that would be useful in preparing aqueous concentrates and systems which could be used to replace certain oil-based compositions of the prior art.